The Higgs boson if it is eventually detected will solve the 'Inflation problem', and turn that postulate from an epicycle, invoked to resolve shortcomings in GR, into a theory verified by laboratory experiment. it will do nothing to resolve the identity of DM.

I voted 'other' as I maintain that DM does exist but that originally it was mainly baryonic in form, that an initial 'IGM' of Omegab ~ 0.22 formed Pop III stars which themselves left IMBHs some gas and dust. This gas and dust then formed the visible matter in the galaxies as we know them, and the IMBH's form the DM.

Note: The Freely Coasting Cosmological model (FCM) produces a Omegab ~ 0.2 from its BBN, and Self Creation Cosmology delivers the strictly linear expansion of FCM. SCC is being tested at this moment as the GPB data is now being processed - results will be known in Summer 2006.

I voted 'other' as I maintain that DM does exist but that originally it was mainly baryonic in form, that an initial 'IGM' of Omegab ~ 0.22 formed Pop III stars which themselves left IMBHs some gas and dust. This gas and dust then formed the visible matter in the galaxies as we know them, and the IMBH's form the DM.

Agreed, Garth, but that aside, would you agree some amount of 'dark matter' is necessary?

I would not claim that there is nothing left to discover in terms of exotic particles, axions or whatever. I'm just wary of using such to resolve the 'galactic rotation curve', 'cosmological missing mass' and 'large structure formation' problems of GR and thereby conclude that a 96% majority of the universe's mass inventory consists of totally unknown forms of DM and DE.

Already we have about 1% of closure density in the form of neutrinos, who knows what else there is to find?

Could the zero point energy of quantum fields be modified by gravity? Might this explain the extra mass around galaxies and clusters, etc? Could this be the dark matter we are looking for?

How does GR square up with QT and the ZPE, a 10140 mismatch?

Some experiment is required, but what?

For information Self Creation Cosmology suggests that the observed ZPE (i.e. Casimir force) is dependent on curvature and tends to zero as r -> infinity. The theory suggests that the Casimir force rounds off at a plate separation too small to be achieved within the Earth's gravitational field but the rounding off would be detectable in the Sun's gravitational field somewhere between the orbits of Jupiter and Saturn with present experimental sensitivities. An experiment could be miniaturised and placed on the 'Pluto Express' or similar to demonstrate whether "the zero point energy of quantum fields is modified by gravity" or not.

However according to SCC this extra (and moderate) ZPE density would not be sufficient to explain DM. In SCC the DM is originally baryonic and may exist today in the form of IMBHs.

Dark matter is one of those things that sounds dubious to everyone when they first hear it. I can assure you, however that those of us in the field are by and large convinced of it. I can't tell you what it is, but I can say what it most probably isn't:

1) Neutrinos - We have a limit on the mass and can calculate their approximate abundance. They appear to contribute negligibly.
2) More careful GR - Standard GR is very well understood and I find it extremely implausible that we would have just overlooked something in modelling the systems.
3) MOND - Although not completely dead, the theory is on its last legs. It can't seem to reproduce the CMB power spectrum or large scale structure and there is still no real theoretical motivation for the "modification" of gravity.
4) Errors in the Data - Dark matter is a many, many-sigma statistical result at this point. There's absolutely no way to do away with it with more careful observations.
5) MACHOs - The microlensing observations in the Milky Way halo and the low value of [itex]\Omega_b[/itex] pretty much rule this out. Primordial black holes are also a possibility, but are also almost ruled out.

Microlensing is the most punishing evidence in favor of DM. I was hardcore against the DM model when it first came out, but, microlensing [and to a certain extent large scale structure studies] convinced me that DM is the only logical explanation.

Microlensing is the most punishing evidence in favor of DM. I was hardcore against the DM model when it first came out, but, microlensing [and to a certain extent large scale structure studies] convinced me that DM is the only logical explanation.

Has it been proven that not any kind of distribution of normal, baryoinic matter could account for DM effects because normal matter would scatter light too much, whereas DM WIMPs would not?

Could the ZPE of QFT have enough energy/mass to produce the same effects as DM. Maybe with very large volumes of space there might be enough energy to bend light and change galatic rotation curves.

To this end, is the ZPE background independent? Or does the energy produced depend on the curvature of the spacetime in which it is calculated?

I'm thinking that the tidal forces of a gravitational gradient (from a nearby galaxy or cluster) will increase the probability that virtual pairs will become permanently separated and survive long enough to produce gravitational effects. (Does any ZPE interact with light and cause gravity?) I think this is so for two reasons: one, the particles involved in Hawking radiation near BHs don't locally know they're near an horizon - locally all they feel is the tidal forces. And two, the equivalence principle equates accelerating frames of reference to those in a gravitational field. This being so, then the Unruh temperature effect for accelerating frames should also apply to frames in a gravitational field, right? This would give a particular temperature (and the particles that produce it) to particular gravity gradient, just as near an horizon. Then more ZPE would congregate around more massive objects (on intergalatic scales) and produce the DM effects, right?

Could the ZPE of QFT have enough energy/mass to produce the same effects as DM. Maybe with very large volumes of space there might be enough energy to bend light and change galatic rotation curves.

To this end, is the ZPE background independent? Or does the energy produced depend on the curvature of the spacetime in which it is calculated?

Einstein was on this track as he continued to develop his theory of General Relativity. By 1920, he was convinced that GR needed a dynamical ether to mediate gravitation and inertia. He also accepted the need for an EM ether to allow for the propagation of light through space, but did not see that the two were united. By 1924, as shown in his paper "On the Ether" he viewed the gravitational and EM ethers as one and the same and was working toward modifying GR to encompass them.

Einstein "On the Ether" said:

The general theory of relativity removes a defect of classical dynamics: in the latter, inertia and weight appear as totally different manifestations, quite independent of one another, in spite of the fact that they are determined by the some body-constant, i.e. the mass. The theory of relativity overcomes this deficiency by determining the dynamical behaviour of the electrically neutral mass-point by means of the geodesic line, in which inertia and weight effects can no longer be distinguished. Thereby it attributes to the ether, varying from point to point, the metric and dynamical properties of the points of matter, which in their turn are determined by physical factors, to wit the distribution of mass or energy respectively. The ether of the general theory of relativity differs from that of classical mechanics or the special theory of relativity respectively, in so far as it is not 'absolute', but is determined in its locally variable properties by ponderable matter. ... The fact that the general theory of relativity has no preferred space-time coordinates which stand in a determinate relation to the metric is more a characteristic of the mathematical form of the theory than of its physical content. ... The metric tensor which determines both gravitational and inertial phenomena on the one hand, and the tensor of the electromagnetic field on the other, still appear as fundamentally different expressions of the state of the ether; but their logical independence is probably more to be attributed to the imperfection of our theoretical edifice than to a complex structure of reality itself.

And on magnetic fields:

Einstein "On the Ether" said:

The earth and sun have magnetic fields, the orientation and sence of which stand in approximate relationship to the axes of rotation of these heavenly bodies. ... It rather looks as if cyclic movements of neutral masses are producing magnetic fields. The Maxwell theory, neither in its original form, nor as extended by the general theory of relativity, does not allow us to anticipate field generation of this kind. It would appear here that nature is pointing to a fundamental process which is not yet theoretically understood.

Einstein was striving for simplification and unity. A polarizable, self-interacting quantum vacuum field would very neatly serve as his GR ether, with no need for additional entities.

Were the early "null' detections of the ether (via ether drift interferometry) actually null?

Dark matter is one of those things that sounds dubious to everyone when they first hear it. I can assure you, however that those of us in the field are by and large convinced of it. I can't tell you what it is, but I can say what it most probably isn't:

1) Neutrinos - We have a limit on the mass and can calculate their approximate abundance. They appear to contribute negligibly.
2) More careful GR - Standard GR is very well understood and I find it extremely implausible that we would have just overlooked something in modelling the systems.
3) MOND - Although not completely dead, the theory is on its last legs. It can't seem to reproduce the CMB power spectrum or large scale structure and there is still no real theoretical motivation for the "modification" of gravity.
4) Errors in the Data - Dark matter is a many, many-sigma statistical result at this point. There's absolutely no way to do away with it with more careful observations.
5) MACHOs - The microlensing observations in the Milky Way halo and the low value of [itex]\Omega_b[/itex] pretty much rule this out. Primordial black holes are also a possibility, but are also almost ruled out.

I totally agree with you SpaceTiger. I can see you have answered "other". Is this because you have some special other candidate in mind, or that you just don't believe in any of the listed candidates, or simply just because you are being "scientific" and reject to answer a question you don't know the answer to?

I totally agree with you SpaceTiger. I can see you have answered "other". Is this because you have some special other candidate in mind, or that you just don't believe in any of the listed candidates, or simply just because you are being "scientific" and reject to answer a question you don't know the answer to?

Mostly the latter. My intuition tells me only that the dark matter is probably a particle of some kind. Beyond that, I don't feel qualified to say anything about exactly which particle it's most likely to be.

Mostly the latter. My intuition tells me only that the dark matter is probably a particle of some kind. Beyond that, I don't feel qualified to say anything about exactly which particle it's most likely to be.

I suspected that.

What about if I force you to pick one kind of particle, what would your answer be then?:tongue2: